1. Field of the Invention
The present invention relates to an apparatus for selecting an image of a specific scene, to a program therefor, and to a recording medium storing the program. More specifically, the present invention relates to an apparatus for selecting images of a desired scene for classifying images represented by digital image data according to scenes, to a program therefor, and to a recording medium storing the program.
2. Description of the Related Art
Research and development of an image classifying method have been started recently. In this method, whether or not images represent a predetermined one of scenes is judged automatically for classifying the images represented by digital image data according to the scenes and for carrying out correction processing or printing corresponding to the scenes.
For example, in Japanese Unexamined Patent Publication No. 11 (1999)-298736, a method is described for specifically selecting an image of sunset. In this method, a product of hue and saturation and a product of hue and lightness of pixels belonging to a range from red to yellow in an image are indicated as a histogram, and the image is judged to be an image of sunset if variance in the histogram exceeds a reference value.
Furthermore, in Japanese Unexamined Patent Publication No. 11 (1999)-196324, a method is described for judging whether an image is a backlight photo or not, with reference to contrast and the like between areas generated by dividing the image into a center area and a peripheral area according to a predetermined manner of division that is common for all images to be judged.
However, characteristics of an image of a specific scene are represented not only by colors and lightness of the entire image but also by layout of a characteristic part having a characteristic color and lightness. For example, in an image of a scene of sunset, the sky which indicates a characteristic of sunset in the most prominent manner is usually laid out in an upper area of the image. However, in the histogram used in the method described in Japanese Unexamined Patent Publication No. 11(1999)-298736, an image having the sunset sky in an upper area thereof is dealt equally with an image of a subject at the center thereof having clothes or the like in a color and lightness similar to those of the sunset sky, which increases erroneous judgment.
Furthermore, even if a characteristic such as colors or lightness of each of the areas generated by division of an image are examined as in the method described in Japanese Unexamined Patent Publication No. 11 (1999)-196324, a change in position or an area proportion caused by a difference in composition or the like cannot be dealt with by the predetermined manner of division. For example, in the case of a scene of sunset, although the sky at sunset is laid out commonly in an upper area of each sunset image, a position of boundary between the sky and other parts (such as skyline) therein varies greatly due to composition adopted by each user. Therefore, if an image is divided according to the predetermined common manner, a part other than the sunset sky may be included in a considerable proportion in an upper area generated by the division. In this case, if a characteristic is examined in the entire upper area, probability of erroneous judgment becomes high.